diff --git a/sql/rpl_mi.h b/sql/rpl_mi.h
index b6ff69d1f64..27a8ae98678 100644
--- a/sql/rpl_mi.h
+++ b/sql/rpl_mi.h
@@ -210,6 +210,16 @@ class Master_info : public Slave_reporting_capability
   void lock_slave_threads();
   void unlock_slave_threads();
 
+  ulonglong get_slave_skip_counter()
+  {
+    return rli.slave_skip_counter;
+  }
+
+  ulonglong get_max_relay_log_size()
+  {
+    return rli.max_relay_log_size;
+  }
+
   /* the variables below are needed because we can change masters on the fly */
   char master_log_name[FN_REFLEN+6]; /* Room for multi-*/
   char host[HOSTNAME_LENGTH*SYSTEM_CHARSET_MBMAXLEN+1];
diff --git a/sql/sys_vars.cc b/sql/sys_vars.cc
index a2101b94a24..5cd33a5bf81 100644
--- a/sql/sys_vars.cc
+++ b/sql/sys_vars.cc
@@ -5199,7 +5199,7 @@ static Sys_var_uint Sys_slave_net_timeout(
 */
 
 ulonglong Sys_var_multi_source_ulonglong::
-get_master_info_ulonglong_value(THD *thd, ptrdiff_t offset) const
+get_master_info_ulonglong_value(THD *thd) const
 {
   Master_info *mi;
   ulonglong res= 0;                                  // Default value
@@ -5207,7 +5207,7 @@ get_master_info_ulonglong_value(THD *thd, ptrdiff_t offset) const
   if ((mi= get_master_info(&thd->variables.default_master_connection,
                            Sql_condition::WARN_LEVEL_WARN)))
   {
-    res= *((ulonglong*) (((uchar*) mi) + master_info_offset));
+    res= (mi->*mi_accessor_func)();
     mi->release();
   }
   mysql_mutex_lock(&LOCK_global_system_variables);
@@ -5277,7 +5277,7 @@ static bool update_slave_skip_counter(sys_var *self, THD *thd, Master_info *mi)
 static Sys_var_multi_source_ulonglong Sys_slave_skip_counter(
        "sql_slave_skip_counter", "Skip the next N events from the master log",
        SESSION_VAR(slave_skip_counter), NO_CMD_LINE,
-       MASTER_INFO_VAR(rli.slave_skip_counter),
+       &Master_info::get_slave_skip_counter,
        VALID_RANGE(0, UINT_MAX), DEFAULT(0), BLOCK_SIZE(1),
        ON_UPDATE(update_slave_skip_counter));
 
@@ -5293,7 +5293,7 @@ static Sys_var_multi_source_ulonglong Sys_max_relay_log_size(
        "relay log will be rotated automatically when the size exceeds this "
        "value.  If 0 at startup, it's set to max_binlog_size",
        SESSION_VAR(max_relay_log_size), CMD_LINE(REQUIRED_ARG),
-       MASTER_INFO_VAR(rli.max_relay_log_size),
+       &Master_info::get_max_relay_log_size,
        VALID_RANGE(0, 1024L*1024*1024), DEFAULT(0), BLOCK_SIZE(IO_SIZE),
        ON_UPDATE(update_max_relay_log_size));
 
diff --git a/sql/sys_vars.inl b/sql/sys_vars.inl
index 3e282de439a..20d7214709e 100644
--- a/sql/sys_vars.inl
+++ b/sql/sys_vars.inl
@@ -2322,10 +2322,10 @@ public:
   like sql_slave_skip_counter are GLOBAL.
 */
 
-#define MASTER_INFO_VAR(X) my_offsetof(Master_info, X), sizeof(((Master_info *)0x10)->X)
 class Sys_var_multi_source_ulonglong;
 class Master_info;
 
+typedef ulonglong (Master_info::*mi_ulonglong_accessor_function)(void);
 typedef bool (*on_multi_source_update_function)(sys_var *self, THD *thd,
                                                 Master_info *mi);
 bool update_multi_source_variable(sys_var *self,
@@ -2334,26 +2334,23 @@ bool update_multi_source_variable(sys_var *self,
 
 class Sys_var_multi_source_ulonglong :public Sys_var_ulonglong
 { 
-  ptrdiff_t master_info_offset;
+  mi_ulonglong_accessor_function mi_accessor_func;
   on_multi_source_update_function update_multi_source_variable_func;
 public:
   Sys_var_multi_source_ulonglong(const char *name_arg,
                              const char *comment, int flag_args,
                              ptrdiff_t off, size_t size,
                              CMD_LINE getopt,
-                             ptrdiff_t master_info_offset_arg,
-                             size_t master_info_arg_size,
+                             mi_ulonglong_accessor_function mi_accessor_arg,
                              ulonglong min_val, ulonglong max_val,
                              ulonglong def_val, uint block_size,
                              on_multi_source_update_function on_update_func)
     :Sys_var_ulonglong(name_arg, comment, flag_args, off, size,
                        getopt, min_val, max_val, def_val, block_size,
                        0, VARIABLE_NOT_IN_BINLOG, 0, update_multi_source_variable),
-    master_info_offset(master_info_offset_arg),
+    mi_accessor_func(mi_accessor_arg),
     update_multi_source_variable_func(on_update_func)
-  {
-    SYSVAR_ASSERT(master_info_arg_size == size);
-  }
+  { }
   bool global_update(THD *thd, set_var *var)
   {
     return session_update(thd, var);
@@ -2367,7 +2364,7 @@ public:
   {
     ulonglong *tmp, res;
     tmp= (ulonglong*) (((uchar*)&(thd->variables)) + offset);
-    res= get_master_info_ulonglong_value(thd, master_info_offset);
+    res= get_master_info_ulonglong_value(thd);
     *tmp= res;
     return (uchar*) tmp;
   }
@@ -2375,7 +2372,7 @@ public:
   {
     return session_value_ptr(thd, base);
   }
-  ulonglong get_master_info_ulonglong_value(THD *thd, ptrdiff_t offset) const;
+  ulonglong get_master_info_ulonglong_value(THD *thd) const;
   bool update_variable(THD *thd, Master_info *mi)
   {
     return update_multi_source_variable_func(this, thd, mi);